1. Field of the Invention
This invention relates to a system for forming a composite from a cyanoacrylate composition and a filler within depressions, holes, cracks or spaces in a substrate. The system also allows for the placement of a cantilevered member in the filled depression, hole, crack or space in the substrate to support a load when the cyanoacrylate has cured.
2. Brief Description of Related Technology
Cyanoacrylate compositions are well known, and widely used as quick setting, instant adhesives with a wide variety of uses. See H. V. Coover, D. W. Dreifus and J. T. O'Connor, “Cyanoacrylate Adhesives” in Handbook of Adhesives, 27, 463-77, I. Skeist, ed., Van Nostrand Reinhold, New York, 3rd ed. (1990). See also G. H. Millet “Cyanoacrylate Adhesives” in Structural Adhesives: Chemistry and Technology, S. R. Hartshorn, ed., Plenun Press, New York, p. 249-307 (1986).
A variety of fillers have been incorporated directly into cyanoacrylate compositions to bring about certain changes in physical properties in one part compositions. For instance, U.S. Pat. No. 2,794,788 teaches thickening of cyanoacrylate adhesives by dissolving therein quantities of polymeric alkyl cyanoacrylates, as well as other compounds including polyacrylates and methacrylates, and cellulose esters such as acetate, propionate and butyrate. U.S. Pat. No. 3,836,377 notes among the additional known thickeners polyvinyl ethers such as polyvinylmethyl ether. U.S. Pat. No. 3,692,752 discloses thickened cyanoacrylates containing certain polyether acrylates/methacrylates, acrylic/methacrylic esters of bis(hydroxyalkyl)phosphonic acid derivatives, and acrylic/methacrylic esters of tris(hydroxyalkyl)cyanuric acid derivatives. The '788, '377 and '752 patents each relate to one part thickened cyanoacrylate compositions containing organic compounds as thickeners.
Various inorganic materials have also been proposed as fillers, which can thicken the composition. In that regard U.S. Pat. No. 3,663,501 teaches preparation of a dental cement containing inert, finely-divided solids such as fused silica, quartz and alumina. Similarly, U.S. Pat. No. 3,607,542 teaches the preparation of a water-resistant cyanoacrylate paste containing insoluble, inert fillers such as salts of calcium, titanium, zinc, tin, aluminum, iron and copper, among others.
U.S. Pat. No. 4,102,945 (Gleave) is directed to and claims a thickened, curable adhesive composition comprising a monomeric ester of 2-cyanoacrylic acid, and for each 100 parts by weight of monomeric ester, about 3 to about 30 parts by weight of an organic material which is an acrylonitrile-butadiene-styrene terpolymer, where the composition has improved peel strength over the corresponding unthickened adhesive.
U.S. Pat. No. 4,105,715 (Gleave) is directed to and claims a thixotropic, curable adhesive composition comprising a monomeric ester of 2-cyanoacrylic acid, and for each 100 parts by weight of monomeric ester, about 5 to about 100 parts by weight of a polyvinylidene fluoride powder. It is also disclosed therein that polycarbonates, polyethylenes, and acrylic block copolymer resins containing saturated elastomer segments may be used. The particle size of the filler is about 2 to 200 microns. These finely-divided organic powders which are not dissolved or not fully dissolved in the cyanoacrylate monomer convert the liquid cyanoacrylate to a non-drip, thixotropic gel or paste.
Despite the state-of-the-art it is not believed that cyanoacrylates have been used as part of a two part system to form together with a filler a composite within a depression, hole, crack or space in a substrate or between two substrates, let alone to anchor placement of a cantilevered member which is capable of supporting a load.
However, other adhesive systems are known for such applications in general. For instance, CHEMOFAST ramcord Befestigungssyteme GmbH has promoted for sale three different “chemical anchoring” systems for heavy load carrying attachments in concrete, solid stone or hollow brick surfaces. These systems are based on one of “reaction resin mortar, epoxy-acrylate-based in cartridges”, “reaction resin mortar, polyester-based” or “reaction resin mortar, vinyl-ester-based styrol-free”.
In each of these systems, their usage is described in terms of drilling a hole in the substrate, cleaning out the drilled hole, and either filling the cleaned drill hole with the reaction resin mortar and then placing a reinforcement bar or threaded rod into the reaction resin mortar filled drill hole or placing a sleeve collar into the cleaned drill hole and filling the collar with the reaction resin mortar and then placing an anchoring element into the reaction resin mortar filled collar within the drill hole, and thereafter curing the reaction resin mortar, say for forty five minutes at room temperature (though other conditions of temperature and time combinations are also disclosed). Once cured, a component may be installed onto the reinforcement bar, threaded rod or anchoring element and torque applied thereto.
While these CHEMOFAST systems have been met with commercial acceptance, it would be desirable to create adhesive systems for such applications that are faster curing at room temperature and that do not require a step of cleaning out the hole, whether the hole was made for the purpose of “chemical anchoring” or whether the hole previously existed and is to be used to “chemically anchor” another article or is simply to be filled. In addition, it would be desirable to create such an adhesive system where the adhesive is dispensed after the filler material, so that there is less opportunity for excess adhesive to be used, thus rendering clean up simpler.
In addition, a system has been offered for sale in Japan, which is seemingly similar to the CHEMOFAST systems, but is based on polyurethane chemistry and includes in the package a series of sponges for placement within the holed prior to dispensing of the polyurethane.
Thus, notwithstanding the state-of-the-technology it would be desirable to provide a composite forming system in which a cyanoacrylate may be applied to a depression, hole or crack in a substrate, into at least a portion of which has been placed a filler, and a composite may be formed within the depression, hole or crack within a period of time of less than about five minutes at room temperature, and when formed such composite is capable of anchoring a cantilevered member which is capable of supporting a load.